Leakproof carton



April 24,1945. E. c. SIEWERT r 2,374,453;

LEAKPROOF CARTON Filed March 13, 1944 2 Sheets-Sheet l April E. c. SlEWERT LEAKPROOF CARTON Filed March 13, 1944 2 Sheets-Sheet 2 1 te t A r; 2 4

LnAKrnooF CARTON Edwin C. Siewert,Wausau, Wis., assignor to, Marathon Corporation, a dorporation of Wis- 'consin Application March 13, 1944, Serial No. 52am 2 Claims.

This invention relates to a paper carton that is leakproo! at the bottom comers.

Manyattempts have been made previously to constructpaper cartons that can be filled with fluid contents without leaking at the bottom corners or seams. Such prior attempts are exem-- plifled by Patents Nos. 1,950,934, March 13, 1934,

I and 1,973,633, September 11, 1934. In such car ton constructions there is a tendency for the liquid in the carton to work its way betweenthe overlapped side walls and thus leak out of the carton. In the construction shown in Patent No. 1,950,934 it is not possible to glue the overlapped sidepanels throughout their entire area as there 7 is an interposed bottom flap of smaller area than bottom flaps ii are hinged to bottom wall 14 along score lines 1 and 8, respectively. The flaps 15 are separated ,from adjacent side panels ll and I! by cut score lines 42, respectively, and by the overlapped side panels so that in actual machine production an unglued channel is always left above the interposed bottom flaps through which the liquid will work its way through to the outside of the carton. Likewise in the carton construction shown in Patent No. 1,973,633, the liquid tends to work through between the abutting edges of the inner flaps interposed between the overlapped side walls.

The disadvantages of such prior constructions are overcome by the present invention by providing a leakproot construction as will be apparentirom the following specification and drawings wherein:

Figure 1 is a plan view of the outer face or the paper blank from which the carton is made,

Figure 2 is a plan view of the inner face of the blank.

Figure 3 is a perspective view or the completed carton made from the blank shown in Figure 1,

Figure 4 is a perspective view of the partially completed carton,

Figure 5 is a perspective view of the completedcarton partially broken away,

Figure 6 is a tragmental perspective view of the lower portion of the carton,

Figure '7 is a plan view 0! Figure 6 partly broken away, and

Figure 8 is a Iragmental sectional view of the cm filled with a liquid.

Referring to the drawings the carton is constructed from an integral blank shown in Figures 1 and 2 made of paper, cardboard and the like.

The blank is suitably scored along-lines i, 2, 3,

l, 'l, 8, 8. 30, 3| and 32 to form a bottom wall ll, a front wall I! anda rearwall l0; Side panels ll and llarehingedtorearwall ll along scored lines I and 2, respectively. Side panels l1. and II are hingedtotront wall is along score cut scores and 56 from adjacent side panels I! and II, respectively. Closure nap 22 is hinged to side panel i2 along score line 6. Closure flap 20 is hinged to side panel ll along score line 5. The sides 60 and 55 of closure flap 20 and sides 51 and SI of closure flap 22 are cut so as not to extend beyond the side wallsof the carton when the flaps are overlapped in the position shown in Figure 5. The length flap 22 is of such dimension that the free edge 62 will not extend be-.

yond the wall of the cartonfwhen the flap is folded to close the carton, as shown in Figure 5.-

Flap 22 is preferably of. such dimension as to fully close the open end of the carton. Closure flap 23 is'hlnged to front wall is along score line 32. This flap is provided with a locking tongue 24.

Closure flap 2| is hinged to rear wall i0 along score line 3. Flap 2i is cut to such dimensions that the free edges 58, 59 and .63 do not extend beyond the walls of the carton in closed position as shown in Figure 3. This flap isprovided with a slit 2! for receiving tongue 24 in locking engagement.

In iorming the carton from the blank previously described, adhesive is applied to the outer sm'taces of side panels i1 and I8 and triangular flaps I! as shown in Figure 1. The bottom flap i5, front wall It and rear wall iii are folded upright in perpendicular relation to the bottom wall II as shown in Figure 4. At the same time side panels ii and is are then folded at right angles to the front wall is and triangular bottom flaps 15 are then brought into contact with the outer faces of side panels l1 and is and adhered thereto throughout their contacting areas. Adhesive is then applied to the inner faces of side panels II and 12. Side panels ill and I2 are then ioldedagainst the adjacent side panels 11 and I9 and adhered thereto and the superim-v In the completed construction of the carton it will be noted that the bottom flaps ilaread- .lines IO andii. respectively.- Triangular shaped" hered: and my retained between the overlapped side panels H and I1, and I2 and l9,:respectively, throughout their entire area. The contacting face portions of the side panels are also adhered throughout their entire area so that no unglued pocket portions exist anywhere at the overlapped side panels.

Triangular bottom flaps is are cut at 42 to facilitate the folding operation during machine production of the carton. A shoulder. portion 43 is provided to ensure against leakage at the cor ners of the carton at the exposed edges 49 and 50 of the side panels II and I2, respectively. It will be noted that the bottom flaps l5 are substantially triangular in shape and their extreme tip portions 10 extend to the top edges 45 and 46 of the carton. By virtue of this construction leakage of any liquid contents A- is obviated so that the carton is leakproof. If any leakage of contents A should occur say between side panels II and II the liquid may travel up to the edge 40 of bottom flap I5, but cannot travel past this line as the glued flap l5 will act as a dam and prevent any liquid from travelling outwardly toward the free edge 49 of side panel ll where it could leak out of the carton. It is thus evident that whether the carton is full or partially filled with liquid contents the triangular flaps l5 serveas an effective dam to prevent any escape of the liquid through the seams of the carton.

Although it is preferred to use triangular shaped cartons made of paper or cardboardare illled with water or other liquids no leakage whatsoever will occur. The present invention thus provides a very satisfactory carton that has many uses for packaging ice cream, lard and other substances that are initially in liquid form and are then congealed for storage and shipment.

Having thus described the novel and essential features of my invention, I claim:

, 1. A carton formed from a single integral blank comprising abottom wall, opposed front and rear' walls hinged to said bottom wall, side panels hinged to said front and rear walls, said side panels being substantially coextensive in 'area, substantially triangular, shaped bottom flaps hinged to said bottom wall, said side-panels being adhered in overlapped relation with the bottom bottom flaps 15, it is obvious that any other suitable shape of bottom flaps I 5 can be utilized provided the flaps extend to the top of the carton to serve as a dam for any liquid escaping between the side panelsas' previously explained.

The present construction provides a very effective leakproof carton construction. When flaps adhered therebetween throughout the contacting faces thereof, the apex of said triangular bottom flaps extending substantially to the upper edge of said overlapped side panels to provid a substantially leakproof carton.

2. A downwardly tapered carton formed from a single integral blank comprising a bottom wall, opposed downwardly'tapered front and rear walls hinged to said bottom wall, downwardly tapered side panels hinged to said front and rear walls, said side panels being substantially coextensive in area, bottom flaps hinged to said bottom wall,

said side panels being adhered in overlapped relation with the bottom flaps adhered therebetween throughout the contacting faces thereof, saidbottom flaps tapering upwardly toward a point and extending substantially to the upper edge of said overlapped side panels to provide a substantially leakproof carton. I

v EDWIN C. SIEWERT. 

